feat(rfq): durably relay provider settlements

[tvolk131]

Summary

• atomically persist the exact signed PSET, raw transaction, txid/wtxid, and an immediately due relay record
• fence access to relay bytes behind durable retry leases and revision-checked outcomes
• add status-first Elements reconciliation for mempool, canonical confirmation, stale-block reorgs, conflicts, policy rejection, and ambiguous broadcasts
• expose the validated relay lifecycle through authenticated status and client recovery
• supervise relay work in the provider daemon, gating new trade admission on relay health without reopening signed inputs
• document the durability, reconciliation, and operations boundary

Correctness properties

• signed artifacts and relay intent commit atomically
• retries always use the exact persisted transaction bytes
• same-txid/different-witness artifacts conflict only when observed in the active mempool or chain
• stale-block observations fall through to stable-tip input checks and exact rebroadcast
• relay leases and outcomes are crash-safe and revision-fenced
• confirmed/conflicted settlements remain monitored for reorgs
• signed allocations never reopen
• relay degradation closes quote/blind/execute admission while status recovery remains available

Verification

• cargo test --locked --workspace
• cargo check --locked --workspace --all-targets
• cargo fmt --all -- --check
• git diff --check

Live Elements process-kill, mempool/confirmation/reorg acceptance, and public-network rollout gates remain explicit follow-up work.

Stacked on #41.

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[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-08-29T04:08:02.425077Z	399464d	PR opened

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